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a part of the amniotic sac that sometimes envelops the head of the fetus at birth.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

great·er o·men·tum

an areolar, four-layer peritoneal fold, formed by the double-layer dorsal mesentery of the stomach (dorsal mesogastrium) descending from the greater curvature of the stomach to fold under on itself and ascend to the transverse colon; the descending and ascending portions fuse, obliterating the inferior recess of the omental bursa, resulting in the four-layer structure that usually hangs over the anterior aspect of the intestines like an apron; components include the following peritoneal ligaments: gastrophrenic, gastrosplenic, splenorenal, and gastrocolic.
Synonym(s): omentum majus [TA], caul (2) , cowl, epiploon, gastrocolic omentum, pileus, velum (3)
Farlex Partner Medical Dictionary © Farlex 2012


n. pl. pi·lei (-lē-ī′)
1. Botany The umbrellalike fruiting structure forming the top of a stalked fleshy fungus, such as a mushroom; the cap.
2. A brimless round skullcap worn by ancient Romans.
3. See caul.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


the cap of a mushroom or toadstool.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
mundula present similar basidioma stature, pileus size and surface, lamellae insertion, stipe size, color and surface, but the pileus color of R.
Table 2 showed the results of the number of pileus of oyster mushroom in every nine (9) days of harvesting on every ten (10) data bags per treatment.
Liu, "Evaluation of ergosterol and its esters in the pileus, gill, and stipe tissues of agaric fungi and their relative changes in the comminuted fungal tissues," Applied Microbiology and Biotechnology, vol.
Pileus: 0.8-3.0cm diameter, slightly umbilicate, surface striated and translucent toward the margin, striated margin, light brown color.
Ma sara un'incoronazione molto particolare: nel Battistero egli indossera con orgoglio non una corona di alloro, di edera o di mirto, ma proprio quel "cappello", il pileus, che gli sbanditi perdonati erano costretti a portare in modo umiliante.
Pileus trama with hyphae (1.5-)3-8 um wide, some globose, up to 30 [micro]m wide, thin-walled, hyaline to brownish, not incrusted.
The females prefer to deposit their eggs in dried mushrooms with intact gills, and this pattern is obtained when using mushrooms harvested before the beginning of the senescence process (margin of pileus plane).
The close-fitting felt cap (Greek pilos, Latin pileus) was the everyday worker's hat--the classical equivalent, I suppose, to the baseball cap.